Conventional light emitting diodes often comprise a light emitting diode chip or die mounted with a metal cup having a highly polished surface. The cup is then filled with an epoxy filler. The finished structures can then be used as a surface-mounted (SMT) light emitting diode (LED).
One drawback of these conventional designs of LEDs is that there is often poor adhesion between the epoxy filler and the metal cup. This, in turn can result in a gap forming between the filler and the cup as the filler expands and contracts during the life cycle of the LED. The expansion and contraction can cause the wire band between the LED chip and the SMT leads to rupture or break. In severe cases, the LED chip itself may rupture.
A need exists, therefore, for a LED which has the reflectivity of a metal cup, but which provides for sufficient bonding between the cup and the filler such that two remain bonded together during the normal life cycle of the LED.